One hundred ninety-nine years ago today, a fleet of British ships spent a full day lobbing mortars and Congreve rockets at Fort McHenry (shown above) in an effort to capture Baltimore during the War of 1812. The British viewed the city as a “nest of pirates” because it was home to many of the privateers that had been preying on British shipping.

When I first started writing my novel The Ambitious Madame Bonaparte, I wasn’t sure whether I was going to portray the Battle of Baltimore. By then, I had read five different biographies of Betsy Bonaparte. None of them answered the question of whether she was in her hometown of Baltimore or in Washington, D.C., when the attack took place.

Then in November 2011, my husband and I traveled to Baltimore, so I could do some research. One place we visited was Fort McHenry. We were lucky enough to be able to hear one of the National Park rangers tell the story of the battle. At one point, he described how many of the residents of Baltimore climbed to their roofs so they could watch the attack and see how it was going. As he spoke, a strange thing happened.

An unexpected wave of fear washed over me, and suddenly I was no longer sitting in the bright November sunshine, listening to a ranger spin a lively tale. I was Betsy, standing on the roof of her childhood home, gripped by the dread of what would happen if the British captured the city. During the early years of her marriage, Betsy and her husband Jerome had often been threatened by British warships who wanted to make a hostage of Napoleon’s brother. Now, she feared for her beloved nine-year-old son. He was a Bonaparte, the nephew of the man the British had been fighting for more than 15 years. As I imagined Betsy’s terror, I began to cry right there in the crowd of tourists. The emotion was so powerful, so icy cold and unsettling, that I couldn’t help myself. After that, I knew with absolute certainty that I had to include the battle in the novel and that I had to portray Betsy’s desperate if somewhat irrational fears that if the British conquered Baltimore, her son would be in danger. It was exactly what I needed to make sense of what had up till then been an impersonal event.